Handle ColumnType.Enum. Fixes #850

In MySQL Server 8.0.21, an INFORMATION_SCHEMA column has changed from CHAR(5) to ENUM. Additionally, this new ENUM column is returned as MYSQL_TYPE_ENUM; other ENUM columns as still returned as MYSQL_TYPE_STRING with ENUM_FLAG set.

This updates the deserialization logic to handle ENUM and SET as strings.

Author: bgrainger

src/MySqlConnector/Core/BinaryRow.cs

@@ -132,6 +132,8 @@ protected override object GetValueCore(ReadOnlySpan<byte> data, ColumnDefinition
 			case ColumnType.Blob:
 			case ColumnType.MediumBlob:
 			case ColumnType.LongBlob:
+			case ColumnType.Enum:
+			case ColumnType.Set:
 				if (columnDefinition.CharacterSet == CharacterSet.Binary)
 				{
 					var guidFormat = Connection.GuidFormat;

src/MySqlConnector/Core/TextRow.cs

@@ -68,6 +68,8 @@ protected override object GetValueCore(ReadOnlySpan<byte> data, ColumnDefinition
 			case ColumnType.Blob:
 			case ColumnType.MediumBlob:
 			case ColumnType.LongBlob:
+			case ColumnType.Enum:
+			case ColumnType.Set:
 				if (columnDefinition.CharacterSet == CharacterSet.Binary)
 				{
 					var guidFormat = Connection.GuidFormat;

src/MySqlConnector/Core/TypeMapper.cs

@@ -208,6 +208,7 @@ public static MySqlDbType ConvertToMySqlDbType(ColumnDefinitionPayload columnDef
 					return MySqlDbType.Set;
 				goto case ColumnType.VarString;
 
+			case ColumnType.VarChar:
 			case ColumnType.VarString:
 			case ColumnType.TinyBlob:
 			case ColumnType.Blob:
@@ -272,6 +273,12 @@ public static MySqlDbType ConvertToMySqlDbType(ColumnDefinitionPayload columnDef
 			case ColumnType.Null:
 				return MySqlDbType.Null;
 
+			case ColumnType.Enum:
+				return MySqlDbType.Enum;
+
+			case ColumnType.Set:
+				return MySqlDbType.Set;
+
 			default:
 				throw new NotImplementedException("ConvertToMySqlDbType for {0} is not implemented".FormatInvariant(columnDefinition.ColumnType));
 			}